Trans isomer is more stable than the Cis isomer.why?

symmetry

The stability difference between the trans and cis isomers can be attributed to the spatial arrangement of the atoms or groups around the double bond in the molecule.

In the trans isomer, the substituent groups (atoms or groups of atoms attached to the double bond) are on opposite sides of the double bond. This arrangement allows for a greater separation between the substituents, minimizing steric hindrance (the repulsive interactions between substituents) and reducing the overall energy of the molecule. The trans isomer exhibits a more extended or linear configuration, which is energetically favorable.

On the other hand, in the cis isomer, the substituents are on the same side of the double bond. This leads to increased steric hindrance between the substituents, causing repulsive interactions and resulting in higher energy for the molecule. The cis isomer is often less stable than the trans isomer.

To determine the stability of trans and cis isomers, experimental techniques like Nuclear Magnetic Resonance (NMR) spectroscopy or computational methods such as quantum chemical calculations can be employed. These methods provide valuable insights into the conformations and relative stabilities of different isomers.